Chinese Optics Letters, Volume. 23, Issue 3, (2025)
Fabrication of Sub-Diffraction Limit High-Aspect-Ratio Nanostructures via Laser Direct Writing [Early Posting]
High-aspect-ratio structures with heights or depths significantly exceeding their lateral dimensions hold broad application potential across various fields. The production of these structures is challenging, requiring meticulous control over materials, scale, and precision. We introduce an economical and efficient approach for fabricating high-aspect-ratio nanostructures using a two-photon polymerization process. This approach achieves feature sizes of around 37 nm with an aspect ratio of 10:1 using commercial photoresists. Offering advantages over traditional techniques like, our approach simplifies operation and enhances design flexibility, facilitating the creation of smaller, more complex high-aspect-ratio structures. The capabilities of this approach are demonstrated by producing arrays of three-dimensional microstructures that exhibit sub-micron scales, extensive periodicity, and pronounced aspect ratios. These developments open new possibilities for applications in biomedical, precision engineering, and optical microdevice manufacturing.